Ford Performance M-6049-Z304DA Cylinder Head

Z-Head - Aluminum - Assembled Heads - 63 cc CNC Combustion Chamber - 204 cc Intake Port/Exhaust 85 cc Cast From Prime A356 T6 Aluminum Heads are Cast w/High Flow Ports 20 Degree Inline Valves 145 lbs. @ 1.80 in. Valve Spring Closed Pressure 358 lbs. @ 1.175 in. Valve Spring Open Pressure Steel Alloy Intake/Exhaust Valve Seats Manganese-Bronze Valve Guides 63cc CNCd Combustion Chamber 204cc Intake Port Volume As Cast 85cc Exhaust Port Volume As Cast Made in the USA Ford Performance Parts - Cylinder Head P/N M-6049-Z304DA: Cast from prime A356 T6 aluminum, these "Z" heads from Ford Racing were designed using solid modeling technology. They feature high-flow ports and steel alloy intake and exhaust valve seats installed (they do require a competition valve job and bowl blending). The manganese-bronze valve guides are installed with a semi-finished I.D. and the combustion chambers are CNC-machined. Laser-cut guideplates are included, and they accept both tapered seat and gasket-style 14mm spark plugs.